Hi Sultanen,
I came across your posts looking for exactly the same answers to the same questions you have. Where are you at with your project?
It all started with this very inspiring Peachy Printer:
The Peachy Printer - The First $100 3D Printer & Scanner! by Rinnovated Design ? Kickstarter
The guy implemented the device McGuyver style as minimalist as it comes, I love it. Plus the Z axle system is revolutionary, I was seduced by its simplicity as opposed to the extremely sophisticated machines you find out there for 10 grand.
So I set out on a journey to look for the same thing (as I missed the deadline), but there is absolutely nothing similar out there.
This laser discussion is very interesting indeed, here is some specs for the Resins they sell at Maker juice (providing resin to peachy), it gives a clear indication of how, at least, this resin reacts to wavelength in terms of absorption:
http://makerjuice.com/docs/SubGPlus-TDS.pdf
Keeping track of the raising resin (floating on water (genius!!!) level could be done with a sensor coupled with the drip counter (
12V Dosing Pump Peristaltic Dosing Head DIY for Aquarium Lab Analytical Water | eBay) to obtain an even more accurate Z axle.
Now the big question: What laser and how to make it move?
I also found a thread on this forum about the use of Galvos apparently it would be difficult to drive it for this very purpose, as someone mentioned it they can be fast, but curing is about being accurate rather than fast. Also level of quality should be obtained with better optics, at this point plastic extrusion reaches 0.1mm accuracy on the z axle, with a very narrow beam, and with fluid z axle movements, quality could improve beyond what we have at the moment in the mainstream.
http://laserpointerforums.com/f47/galvos-compatibility-arduino-71292.html : Galvos DO NOT like PWM. ==>
Unless there is a definite answer for Glavos. I would be tempted to go with direct movements even if with inertia (especially if the bulk of the laser is on the moving head) they would limit speed due to mechanical factors, where I suspect galvos could go way faster with the right x-y-z setup. But he galvos way seems to be uncharted territory where there are drivers and open source software for 3d printing for stepping motors already. Porting this onto Galvos would imply rewriting the code. There was a PCB (arduino shield) drawn by someone on this forum to link Aduino and Galvos together but I can't find it anymore.
But if you look at the peachy printer they are using the sound card and converting the sound into variations of angle of home made galvos, he used that shortcut, but the sound card being 2 channels (x,y), apparently, he cannot stop the laser when he wants resulting in a printing logic pretty much like extrusion, with continuous output and all it implies.
I like the idea of being able to mill/engrave your parts after printing, even better would be scanning them initially (you basically would need a camera and a line for laser: I have seen it made with glass stem ==>I am sure there is better lenses than that?) the rest would be done by software, there are plenty of options for that, but the good thing the laser is already there.
Now the big question would be what laser would work for the 3 operations, and how would we modulate it (with optics and intensity) in order to obtain Scanner+Printer+Milling results.
My concern is also security, as the laser would have to be very mobile for scanning, yet less for printing and milling.
Great forum, very exciting times!!
Happy New Year to everybody!!
Be
